code: def register_backend(backend_cls: Type[BaseActorBackend]):
      _scheme_to_backend_cls[backend_cls.name()] = backend_cls
      register_backend_context(
          backend_cls.name(), backend_cls.get_context_cls()
      )
      register_backend_driver(
          backend_cls.name(), backend_cls.get_driver_cls()
      )
      return backend_cls
  
file_path: mars/mars/oscar/backend.py
imports: from abc import ABC, abstractmethod
  from typing import Dict, Type
  from .context import register_backend_context
  from .driver import register_backend_driver
label_desc: Use image node_id 1 for calling a global function with example usage: register_backend(backend_cls) and returns: backend_cls